论文部分内容阅读
合成了手性吡啶醇二氧合钼(VI)及二氧合钨(VI)配合物,采用这两种配合物作为催化剂,实现了在水中对顺丙烯膦酸(CPPA)的催化不对称环氧化.这两种催化剂不溶于水,因此,这是一个发生在固液两相界面上的异相催化不对称环氧化反应.其中手性吡啶醇二氧合钼在0℃下的对映选择性ee值达到71%;加入相转移催化剂四正丁基溴化铵,催化剂的活性和对映选择性有显著提高,其中手性吡啶醇二氧合钨在50℃下ee值由54%提高到78%.手性吡啶醇二氧合钼和二氧合钨催化剂可以回收再使用.
The complexes of chiral pyridyl alcohol dioxo molybdenum (VI) and dioxotungsto (VI) were synthesized, and the catalytic asymmetric ring of cis-para-phosphonic acid (CPPA) Oxidation of these two catalysts are insoluble in water, therefore, this is a heterogeneous catalytic asymmetric epoxidation occurs at the solid-liquid interface, where the chiral pyridine alcohol dioxomolybdenum at 0 ℃ pairs of The ee value of selectivities reached 71%. The addition of phase transfer catalyst tetra-n-butylammonium bromide significantly increased the activity and enantioselectivity of the catalyst. The ee value of chiral pyridine diol oxide at 50 ℃ was 54 % To 78%. Chiral pyridyl alcohol molybdenum dioxide and dioxo-tungsten catalyst can be recycled and used.